A058164 Number of labeled lattices with a fixed bottom.

1, 1, 2, 9, 76, 1065, 22566, 674611, 27019896, 1393871121, 89805306250, 7051089328371, 661327038073428, 72882388902988561, 9308502142507505406, 1361778362223282167235, 225917426273413368357616, 42135305039539420956486369, 8768279861975723002123310226

Offset: 1

Author

Christian G. Bower, Nov 15 2000

Keywords

• nonn
• hard

Crossrefs

Main diagonal of A058160.

Cf. A055512, A058165.

Programs

Mathematica

A055512 = Cases[Import["https://oeis.org/A055512/b055512.txt", "Table"], {, }][[All, 2]];
a[n_] := A055512[[n + 1]]/n;
a /@ Range[18] (* Jean-François Alcover, Jan 02 2020 *)

Formula

a(n) = A055512(n)/n = A058165(n)*(n-1).

Extensions

a(18) from Jean-François Alcover, Jan 02 2020

a(19) from the data at A055512 added by Amiram Eldar, Jul 22 2025